1. Field of the Invention
The present invention relates to a hinge mounted between a cover and a base of an electrical appliance, especially to a stable hinge that securely holds the cover in position and prevents the cover from shaking.
2. Description of the Prior Art
Electrical appliances such as notebook computers, cell phones, etc. have a panel, a base and a conventional hinge. The conventional hinge connects the panel to the base along a transverse axis and a longitudinal axis to allow the panel to pivot and turn relative to the base. When the conventional hinge pivots along the transverse axis, the panel is opened or closed relative to the base. When the conventional hinge pivots along the longitudinal axis, the panel turns left or right relative to the base. To hold the cover in position when the conventional hinge pivots around the longitudinal axis the conventional hinge has a first positioning element, a second positioning element and a spring. The first positioning element rotates relative to the second positioning element. The first and second positioning elements have at least one corresponding protrusion and detent. The spring pushes the first and second positioning elements against each other. Therefore, the protrusion selectively engages the detent to hold the cover in position.
When the first positioning element rotates relative to the second positioning element and the protrusion does not engage the detent, the spring pushes the first and second positioning elements tightly against each other.
Consequently, the necessary force to rotate the first positioning element relative to the second positioning element is greater than the necessary force to engage the protrusion with the detent. Immediately prior to the protrusion engaging the detent a greater force is applied to the cover to rotate the first positioning element relative to the second positioning element. Therefore, too much force is applied to the cover at the instant when the protrusion engages the detent. Too much force easily causes the protrusion to disengage from the detent or the cover to shake and damage a panel in the cover.
To overcome the shortcomings, the present invention provides an intensifying-positioning and preventing shaking hinge to mitigate or obviate the aforementioned problems.